The present invention relates to a side airbag apparatus that is deployed and inflated at a side of an occupant of a vehicle.
When an impact that is equal to or greater than a predetermined value is applied to a body side portion of a vehicle, a typical side airbag apparatus inflates and deploys an airbag at a side of an occupant to reduce the impact applied to the occupant, thereby protecting the head, thorax, or lumbar region of the occupant. To instantly inflate and deploy the airbag, a gas generator of a side airbag apparatus discharges high pressure gas into the interior of the airbag.
Side airbag apparatuses are required not only to simply inflate and deploy an airbag, but also, to inflate and deploy an airbag in a desired state or in a desired position. Therefore, not only for instantly inflating and deploying an airbag, but also for inflating and deploying airbag in a desired state or in a desired position, it is important to control the behavior of the airbag when being inflated and deployed.
For example, Japanese Laid-Open Patent Publication No. 2006-35988 discloses a side airbag apparatus desired for controlling the behavior of an airbag when being inflated and deployed. The side airbag apparatus disclosed in the document has a belt for preventing an airbag from being inflated and deployed at a position displaced from a desired position due to forward inclination of the airbag. That is, the belt of the side airbag apparatus of the document pulls the airbag rearward with respect to the occupant, thereby guiding the airbag to the desired position. In this manner, the side airbag apparatus controls the behavior of the airbag when being inflated and deployed.
However, in the case of the side airbag apparatus disclosed in the document, the inflated and deployed airbag can be inclined inward of the vehicle, or toward an occupant, depending on the shape of the door trim that forms the body side portion of the vehicle. In such a case, the degree of inward inclination of the airbag may be predicted, and the height of the airbag may be increased in accordance with the predicted inclination, so that the head of an occupant is protected. However, according to this configuration, if the airbag is inflated and deployed upright instead of being inwardly inclined, the airbag is likely to hit the roof of the vehicle.